Cepheid Xpert®C. difficile assay targets the tcdB gene (detecting toxin B). Real-time PCR and Reverse Transcriptase Polymerase Chain Reaction (RT-PCR) processes are utilized. The assay is a rapid automated test for qualitatively detecting toxins from unformed (liquid or soft) stool samples. Testing is performed on one of the Cepheid analyzer platforms. Cepheid has both tabletop and walk-away instrumentation.
Roche Diagnostics C. difficile assay also targets the tcdB gene. This assay utilizes real-time PCR (nucleic acid test) on the cobas® Liat® System, a small point-of-care molecular analyzer. The cobas® 4800 System can also perform the C. difficile assay for higher throughput.
As demonstrated by these examples (note, many other options are available or coming available as of this writing), an assay is typically marked by its target (gene, in this case). The assay may be run on:
- small point-of-care instruments
- small tabletop instruments
- large throughput walkaway instruments
Determining the specific laboratory's need before purchasing and implementing any instrumentation is essential.
